Search found 21 matches

by StephanieDoan3B
Sat Dec 09, 2017 11:54 am
Forum: Conjugate Acids & Bases
Topic: Drawing resonance when comparing acid strength
Replies: 1
Views: 166

Drawing resonance when comparing acid strength

When drawing Lewis structures of HClO, HClO2, HClO3, HClO4 to compare acid strength due to electron withdrawing atoms, do we need to draw all of the resonance structures of HClO4 and HClO3?
by StephanieDoan3B
Wed Dec 06, 2017 10:33 pm
Forum: Bronsted Acids & Bases
Topic: 12.9(b)
Replies: 1
Views: 136

12.9(b)

Which of the following reactions can be classified as reactions between Brønsted acids and bases? For those that can be so classified, identify the acid and the base. NH4I(s) --> NH3(g) + HI(g) What makes NH4+ a Bronsted acid? Isn't it NH4I in solid form not aqueous on the left side of the reaction?
by StephanieDoan3B
Sun Dec 03, 2017 4:30 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Notes on 11.37
Replies: 3
Views: 255

Re: Notes on 11.37

It is a rule. When the coefficients in an chemical equation is multiplied by 2, the k is squared. This is a rule when manipulating equilibrium constants.
by StephanieDoan3B
Sun Dec 03, 2017 4:26 pm
Forum: Coordinate Covalent Bonds
Topic: Monodentate, Tridentate
Replies: 1
Views: 386

Re: Monodentate, Tridentate

You can draw the Lewis structure and see where lone pairs can possibly be contributed to the coordinate covalent bond. But for the most commonly used ligands, it would most convenient to memorize if they are mono, bi, tri, etc. -dentate.
by StephanieDoan3B
Fri Nov 24, 2017 12:19 am
Forum: Hybridization
Topic: Nitrogen hybridization
Replies: 2
Views: 164

Nitrogen hybridization

It was stated, "The promotion of electrons will occur if, overall, it leads to a lowering of energy by permitting the formation of more bonds." How come Nitrogen can be hybridized to sp3 if the number of possible bonds (3) doesn't' increase after hybridization?
by StephanieDoan3B
Thu Nov 23, 2017 1:02 pm
Forum: Hybridization
Topic: 4.73
Replies: 2
Views: 135

Re: 4.73

There are no unpaired electrons anywhere in CH2, and there is an even number of electrons total, so it cannot be a radical.
by StephanieDoan3B
Thu Nov 23, 2017 12:58 pm
Forum: Hybridization
Topic: Valence/valency?
Replies: 1
Views: 116

Valence/valency?

The book states, "It looks as though a carbon atom should have a valence of 2 and form two perpendicular bonds, but in fact it almost always has a valence of 4 (it is commonly “tetravalent”)..." Valence is not the number of valence electrons because Nitrogen's valency is 3. Could someone p...
by StephanieDoan3B
Sun Nov 19, 2017 8:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Octahedral vs Trigonal Bypyramidal family
Replies: 3
Views: 203

Re: Octahedral vs Trigonal Bypyramidal family

Every angle in an octahedral structure is 90 degrees. In other words, the orientation of the molecule doesn't matter, so the electron density you choose for the placement of the first lone pair doesn't matter.
by StephanieDoan3B
Sun Nov 19, 2017 7:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar ve non polar [ENDORSED]
Replies: 7
Views: 356

Re: Polar ve non polar [ENDORSED]

Yes, polar vs. non polar is geometrically unequal vs. equal distribution of negative charge in the atom.
by StephanieDoan3B
Wed Nov 08, 2017 3:20 pm
Forum: Resonance Structures
Topic: Formal Charge vs. Electronegativity
Replies: 1
Views: 190

Formal Charge vs. Electronegativity

For example, in SO2, the most stable structure is O=S=O which gives all three atoms formal charge of zero. However, O=S-O and O-S=O also exist, giving formal charge of -1 to the oxygen attached by single bond and formal charge of +1 to the central S atom. This would also make sense because O is more...
by StephanieDoan3B
Wed Nov 08, 2017 3:15 pm
Forum: Resonance Structures
Topic: 3.57 hydrogen sulfite
Replies: 1
Views: 141

Re: 3.57 hydrogen sulfite

Oxygen is more electronegative than sulfur and would attract the hydrogen more strongly than sulfur does.
by StephanieDoan3B
Sun Nov 05, 2017 9:48 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 902910

Re: Post All Chemistry Jokes Here

(Not exactly a joke but a cheeky pickup line)
Can I steal an electron so you can be my +1 to _____?
by StephanieDoan3B
Sun Nov 05, 2017 12:52 am
Forum: Formal Charge and Oxidation Numbers
Topic: Sulfur Dioxide?
Replies: 3
Views: 249

Sulfur Dioxide?

Why are there three resonance structures for SO2 when the one with two double bonds has the lowest formal charge? Why would the other two structures (one double, one single) be allowed to exist when they have higher formal charge?
by StephanieDoan3B
Wed Oct 25, 2017 5:10 pm
Forum: Trends in The Periodic Table
Topic: Effective Nuclear Charge Down a Group [ENDORSED]
Replies: 1
Views: 729

Effective Nuclear Charge Down a Group [ENDORSED]

Does effective nuclear charge increase or decrease down a group? And as we move far down the table, what role do d orbitals play in shielding?
by StephanieDoan3B
Wed Oct 25, 2017 12:08 pm
Forum: Trends in The Periodic Table
Topic: Across a period vs. Down a group
Replies: 3
Views: 218

Re: Across a period vs. Down a group

I don't think we have to or are able to use trends to compare atoms of elements not in the same period or group.
by StephanieDoan3B
Sun Oct 22, 2017 1:16 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: P orbitals
Replies: 4
Views: 447

Re: P orbitals

All three orbitals have the same energy, and the electron will fill any of them first. We designate that px is filled first, then py, and pz because of convention.
by StephanieDoan3B
Sun Oct 22, 2017 12:57 pm
Forum: Quantum Numbers and The H-Atom
Topic: 4s 3d or 3d 4s?
Replies: 3
Views: 290

4s 3d or 3d 4s?

When filling up orbitals with electrons, we fill 4s before 3d. However, we write the electron configuration of V, for example, as [Ar] 3d3 4s2 because here, the 4s is now higher energy than the 3d. Does this mean that the energy levels of orbitals change relative to each other when they become fille...
by StephanieDoan3B
Sat Oct 14, 2017 4:15 pm
Forum: Properties of Light
Topic: Light as a wave or a particle [ENDORSED]
Replies: 2
Views: 166

Re: Light as a wave or a particle [ENDORSED]

Light acts as both a wave and a particle (wave-particle duality) but both natures have never been captured simultaneously in the same experiment. De Broglie's equation, λ=h/mv, illustrates this duality well because λ is wavelength (property of a wave) and m is mass (property of a particle.
by StephanieDoan3B
Sat Oct 14, 2017 4:10 pm
Forum: Properties of Light
Topic: Balmer and Lyman Clarification [ENDORSED]
Replies: 3
Views: 160

Re: Balmer and Lyman Clarification [ENDORSED]

Yes, these series apply only to Hydrogen because electron interaction for atoms with more than one electron will be much more complex. The electrons would interact with other electrons due to electrostatic forces, not accounted for here.
by StephanieDoan3B
Thu Oct 05, 2017 10:51 pm
Forum: Balancing Chemical Reactions
Topic: Order of Elements to Balance [ENDORSED]
Replies: 5
Views: 414

Re: Order of Elements to Balance [ENDORSED]

Yes and if you have a molecule with a single compound, like O2 or N2, keep that for last because it's the easiest to manipulate.
by StephanieDoan3B
Thu Oct 05, 2017 10:48 pm
Forum: Significant Figures
Topic: Clarification
Replies: 4
Views: 257

Re: Clarification

The book and a previous post from a Moderator said to keep as many sig figs in your calculator as possible and round at the very end. But for problems like combustion, there is a step of addition and/or subtraction (of masses), so I don't know if we have to take off the significant digits based on t...

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